A major international climate conference kicked off Sunday in Poland.

For the next two weeks, leaders from around the world will meet to talk about how to reduce global greenhouse gas emissions and support those communities that are already being affected by climate change.

It is the most important climate meeting since 195 countries, including the U.S., signed the landmark Paris Agreement in 2015 and promised to set specific emissions reduction targets. The U.S. said it would reduce greenhouse gas emissions by 26 to 28 percent by 2025.